Build my own saddle-bags!

nice job
your bike looks happy with the new bags

nice pipe!

How about a step-by-step, including pictures, where you got the materials, and a list of tools needed. Perhaps the mods could even make a sticky out of it?

Very nice leather work and handsome bags!
Making bags like that without a sewing machine capable of stitching leather would be difficult, in my opinion, unless the leather is very thin. The old Viking Sewing machines can do it since they have a gear down mechanism so you can punch through multiple layers of something like elk hide. I may do a pair of saddle bags out of harness leather this fall or winter and if so will do a step by step... which would use just simple hand tools like a razor knife, awl, sinew and a pair of harness needles. If you are not familiar with sewing machines in general, stitching leather on a sewing machine takes some practice and working on something simple first would be a good idea, I think. But working with harness leather requires no machine, just some patience and skill with your hands.
SB

Silverbear, I just looked at a website that sells harness leather, but it was a little confusing. They sell it in different weights and thicknesses and such, it seems like they charge per square foot, but you have to buy so many square feet, which I guess is what they call a side? If you were going to make saddle bags, what weight and thickness would you use, and how many square feet would you order? Perhaps you could tell me where you buy yours?

Mine is left over from 20-30 year ago when I raised Indian ponies and made my own horse tack, so I have no idea what weight it is. For making harnesses you're concerned mostly about strength. I was skidding logs out of the forest, so it had to be strong. Saddlebags don't need the strength so much as if you want more of a motorcycle look, the thickness of the leather matters. Thick enough to be on the stiff side. A saddle shop or a leather shop might be able to connect you with what you want. You don't want to buy a whole side of leather as it is much more than you'll want or need. I'll do a tutorial when I make my own which won't be until next winter probably. It is better to explain as you are doing with photos to illustrate than to try to make a reply in a post.
It will cost more than you might imagine, although prices of thirty years ago won't help me estimate. I would make pattern pieces first. Then you know what you need and if you went to a shop might be able to buy smaller pieces for less money than a large one you cut up. If you want to know what the leather looks like it is the same as what I used for Tinsmith's vintage seat. Also what I use for my v8 gas tanks. Mostly because that's what I have.
SB